Utilization of lactoferrin to inhibit E. coli and S. aureus isolates from milk and kariesh cheese

Abstract

This study aims identify E. coli and its β-lactamase encoding genes, S. aureus and its enterotoxin genes isolated from milk and Kariesh cheese. Moreover, we evaluated the antibacterial effect of lactoferrin against these pathogenic bacteria. Sixty samples in total (30 each of raw milk and Kariesh cheese) were collected from various retail-markets in Kafrel-Sheikh Governorate. The percentage of E. coli isolates found in raw milk and Kariesh cheese reached 43.3% and 36.6%, respectively, while S. aureus isolates were recorded at 50% and 23.3% (from raw milk and Kariesh cheese). Twenty-four strains of E. coli were serogrouped, of which 3 strains out of 24 were O17, O91 and O159, 6 strains were O127 and 9 strains were O26. PCR analysis for β-lactamase encoding genes in E. coli indicated that all eight isolates were 100% positive for blaTEM and blaSHV genes while 5 (62.5%) S. aureus isolates were positive for enterotoxin production. Five (62.5%) isolates produced Seb, 2(25%) produced Sec while the Sea gene was not detected in S. aureus isolates. The results indicate that lactoferrin 5% had a significant inhibitory effect on S. aureus and E. coli when they were inoculated into Kariesh cheese. The findings show that dairies didn't take enough hygiene precautions, and we advise following stringent hygiene procedures when dairy products are milked, processed and distributed. To control the growth of E. coli and S. aureus in dairy products,lactoferrin is thought to be a potential strategy.

Keywords

• dairy products
• lactoferrin
• pathogenic bacteria